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771.
772.
Justyna Brasuń Marek Cebrat ?ukasz Jaremko Olimpa G?adysz 《Journal of inorganic biochemistry》2009,103(7):1033-1038
We have characterized the interaction between the Zn2+ ions and the histidine analogues of oxytocin and arginine-vasopressin. Potentiometric methods were used for the determination of the stoichiometry of the complexes formed and the calculation of their stability constants. The NMR measurements revealed detailed structures of the complexes and confirmed the binding mode at physiological pH. 相似文献
773.
We present an electrochemical and optical characterization of 5,10,15,20-tetraphenylporphyrin tin(IV) dichloride (Sn–tpp) in terms of its potential use as a hybrid proteins’ label. Our research comprised Sn–tpp and Sn–tpp in the presence of model proteins selected as to mimic a receptor or surface blocking agents: bovine serum albumin, ovalbumin, and immunoglobulin G. In the course of the study, we determined optimal conditions for analysis by means of differential pulse voltammetry, ultraviolet–visible spectrophotometry, and spectrofluorimetry. In electrochemical detection, the influence of the working electrode, solvent, and supporting electrolyte was examined. Displacements of the received signals along the potential axis (a shift of the potential) and changes in signal intensities due to the addition of proteins were observed and analyzed. Simultaneously, the suitability of Sn–tpp as a label in optical detection mode was assessed by using spectroscopic techniques. The obtained results prove Sn–tpp to be applicable in dual and triple detection systems. Such an approach will improve the reliability of the analysis and, at the same time, will allow for widening the range of the linear response with some overlapping ranges of concentrations. 相似文献
774.
Angiotensin-converting enzyme (ACE) activity in serum and lung tissue from both normotensive Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR) was determined at six different circadian times. In WKY rats serum ACE varied significantly within 24 h, mainly due to reduced enzyme activity at 12:00 h. In SHR the 24-h profile of serum ACE did not exhibit time-dependent differences. Mean serum ACE activity over 24 h was significantly higher in WKY than in SHR. In lung tissue ACE activity did not depend on the circadian time in either strain. Mean enzyme activity in lung tissue was not different between WKY and SHR. We conclude that circadian changes in the activity of serum and tissue ACE are unlikely to play an important role in the regulation of the circadian blood pressure profile in both normotensive and spontaneously hypertensive rats. 相似文献
775.
Julianna Kurlenda Mariusz Grinholc Grzegorz Węgrzyn 《World journal of microbiology & biotechnology》2008,24(4):591-594
Methicillin-resistant strains of Staphylococcus aureus (MRSA) are important etiological factors responsible for hospital-acquired infections. The aim of this study was to analyze
the influence of the presence of emp, pls and cna genes on the pathogenicity of MRSA strains. The presence of these genes was tested by PCR in 302 MRSA strains isolated from
hospitalized patients and from carriers. For each tested gene, proportions of positive and negative strains were similar among
the infected patients and carriers. We did not find any obvious correlation between the presence of the three tested genes
and the infectivity of strains. Our results may also suggest that a lack of emp and presence of pls may correlate with reduced virulence of these strains. 相似文献
776.
Blazej Rubis Hanna Holysz Marta Gladych Ewa Toton Anna Paszel Natalia Lisiak Mariusz Kaczmarek Johann Hofmann Maria Rybczynska 《Molecular biology reports》2013,40(8):4995-5004
The aim of the study was to analyze the consequence of silencing genes coding for the key subunits of the telomerase complex, i.e. TERT, TERC and TP1 in human breast cancer MCF7 and MDA-MB-231cells. The transfection was performed using Lipofectamine2000 and pooled siRNAs. The cytotoxic and/or antiproliferative effect of siRNA was measured by the SRB assay, the cell cycle was analysed by flow cytometry and DNA fragmentation by TUNEL analysis. Telomerase activity was assessed by TRAP, followed by PAGE and ELISA assays. Telomerase downregulation was also assessed using qPCR in order to estimate the changes in the expression profile of genes engaged in apoptosis. It was revealed that treatment of breast cancer cells with different siRNAs (100 nM) resulted in a cell type and time-dependent effects. The downregulation of telomerase subunits was followed by reduction of telomerase activity down to almost 60 % compared to control cells. However, a significant effect was only observed when the TERT subunit was downregulated. Its silencing resulted in a significant (p < 0.05) increase of apoptosis (over 10 % in MCF7 and about 5 % in MDA-MB-231 cells, corresponding to the Annexin V assay) and DNA fragmentation (almost 30 % in MCF7 and over 25 % in MDA-MB-231 cells). Interestingly, also several proapoptotic genes were induced after the downregulation of the key telomerase subunit, including Bax, Bik or caspase-1 and caspase-14, as well as NGFR and TNFSF10 which were upregulated twice and more. 相似文献
777.
Sebastian Gnat Dominik Łagowski Mariusz Dyląg Jessica Zielinski Aneta Nowakiewicz 《Journal of biophotonics》2021,14(10):e202100150
The intense search for the “Holy Grail” of antifungal therapy can be observed today. The searches are not limited only to discovery of potential antifungal drugs, but also new therapeutic strategies involving the use of chemosensitizers to achieve synergistic effect or physicochemical factors inducing stress conditions in fungal cells. In this study was examined in vitro effectiveness of photodynamic antifungal strategy with methylene blue using a light beam with a wavelength equal to 635 nm toward the Trichophyton verrucosum susceptible and itraconazole- and/or fluconazole-resistant strains. Methylene blue used at concentration equal to 5 μg/mL and in the presence of 40 J/cm2 of light energy showed fungicidal effect toward the susceptible strains. However, for azole-resistant isolates, only the energy dose equal to 60 J/cm2 at 5 μg/mL of methylene blue allowed to kill the pathogen. This study confirms that methylene blue induced by red light has a definite inhibitory effect on zoophilic dermatophytes. 相似文献
778.